This invention relates to body fluid absorbent sanitary article such as a disposable diaper, a sanitary napkin, a liquid-absorbent pad for an incontinent patient or the like.
Japanese Patent Application Publication No. 1999-318976A describes a disposable diaper comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between these two sheets, longitudinally configuring front and rear waist regions and a crotch region extending between these two waist regions, wherein the diaper is formed over its approximate rear half as viewed longitudinally thereof with a plurality of ridges made of absorbent material covered with a liquid-pervious sheet. The ridges transversely extend on the inner surface of the diaper and each pair of the adjacent ridges are longitudinally spaced apart from each other by a predetermined dimension. With such known diaper, the ridges serve as barriers to restrict or prevent excretion from flowing forwardly of the diaper and at the same time to prevent excretion from leaking rearwardly of the diaper.
The Publication describes that the preventive effect for rearward leakage of excretion can be significantly improved since the absorbent material of the ridges is able to absorb moisture contained in excretion. However, it is impossible for the absorbent material of the ridges to absorb solid substances contained in excretion of high viscosity such as loose passage or liquid feces. Consequently, such solid components may stay on the outer surface of the topsheet exposed between each pair of the adjacent ridges or on the outer surface of the liquid-pervious sheet covering the ridges and these solid components may stick to a wearer""s skin.
It is an object of this invention is to provide a body fluid absorbent sanitary article adapted to minimize an anxiety that excretion of high viscosity such as loose passage, liquid feces or menstrual discharge might stick to a wearer""s skin.
According to this invention, there is provided a body fluid absorbent sanitary article comprising an absorbent structure which includes an absorbent core and an absorbent upper panel which is formed with a fibrous web having a compressive recovery elasticity and attached to an upper surface of the absorbent structure, the absorbent upper panel having a plurality of openings extending through the absorbent upper panel in a thickness direction thereof and spaced one from another in a direction intersecting the thickness direction and a wall defining each of the openings wherein the wall has a fiber density grade which is higher in an upper region of the wall and lower in a lower region of the wall lying adjacent an upper surface of the absorbent structure.
The body fluid absorbent sanitary article according to this invention enables high viscosity excretion such as loose passage, liquid feces and menstrual discharge to flow into the openings of the absorbent upper panel without permeating into the high density fibrous layer of the wall. Within the openings, most of a moisture content of the high viscosity excretion permeates through the topsheet into the absorbent structure and partially permeates into the low density fibrous layer. The portion of the moisture content having permeated into the low density fibrous layer moves from the low density fibrous layer toward the upper surface of the absorbent structure and permeates through the upper surface into the absorbent structure. Within the openings, a solid content of the high viscosity excretion permeates into the low density fibrous layer. In this manner, there is no anxiety that the high viscosity excretion might stay on the top surface of the panel. In other words, the high viscosity excretion is normally spaced apart from the wearer""s skin and a possibility that the high viscosity excretion may stick to the wearer""s skin can be minimized. Even if the panel is collapsed under the wearer""s body weight, the high viscosity excretion is prevented by the high density fibrous layer of the wall from flowing back to the top surface of the panel.
Urine is absorbed by the high density fibrous layer of the wall and gradually permeates from the high density fibrous layer into the low density fibrous layer. Then, urine flows from the low density fibrous layer toward the upper surface of the absorbent structure and permeates through the upper surface into the structure. Within the openings, most of urine permeates through the upper surface into the structure and partially permeates into the low density fibrous layer. The portion of urine having permeated into the low density fibrous layer flows from the low density fibrous layer toward the upper surface of the absorbent structure and permeates through the upper surface into the structure.